Integrating TaskService with jbpm-console

[bpmn2user]

I am wondering why the demo human taskservice is not integrated with jbpm-console for the ease of deployment (e.g., startup servlet) instead of running it as a separate ant task?

[bpmn2user]

I have integrated this human task as part of jbpm-console mainly for the following reasons

• I do not need to maintain another job to run human task and the installation becomes simply dropping the war files in Tomcat.
• I can use Tomcat logs to see if there is any problem in calling Humantasks from Tomcat

Anyway, here are the details if any one wants to  integate with Tomcat6.

Modify web.xml in jbpm-console's war file to include a human task startup servlet.

e.g.,

<servlet>

        <servlet-name>HumanTaskStartupServlet</servlet-name>

        <servlet-class>com.sample.HumanTaskStartupServlet</servlet-class>

         <load-on-startup>2</load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>HumanTaskStartupServlet</servlet-name>

         <url-pattern>/HumanTaskStartupServlet/*</url-pattern>

    </servlet-mapping>

Copy the humantask compiled class to WEB-INF/classes diectory of jbpm-console

[bpmn2user]

Here are  the sample human task servlet and web.xml files used in Tomcat

[salaboy21]

Great, sounds good for testing purposes but I'm not sure that is the best for productions applications. Imagine that if you put multiple applications on the same tomcat instance and one application consume all the memory, your jBPM console will stop working as well as all your task clients, because the task server is running inside tomcat.

This idea also breaks the scalability that gives you the Task Server running decoupled from tomcat in a different JVM instance.

But if it works for you congrats!

[bpmn2user]

That is a good point. I am not sure how much  resource intensive this human task service is?

Well! We are already running two war files in the same JVM instance (jbpm-console and gwt-console-derver). We might as well have them installed in two seperate JVM instances. I am looking at the deployment option, i.e  using a war file instead of running a standalone job with an ant task.

[krisverlaenen]

Nice !

I had already identified this as a possible improvement: https://issues.jboss.org/browse/JBPM-3013

This will help me speed up the fix

Mauricio is correct in saying that this is just one possibility and that this does not necessarily is the ideal solution for everyone, but the installer simply creates a demo setup, in which case I think it makes sense, as it probably is a little easier for people to deploy a war to get the task service running rather then executing a separate Java program.

Kris

[roxy1987]

Hi Bpmn2user,

It has been quite some time since you posted this.

I tried using the servlet you attached above to get rid of human task service related stuff. It could not connect to the task client. Below is the trace. COuld you please take a look at it and lemme know what I might have done wrong.

• URL: 'http://localhost:8080/gwt-console-server/rs/tasks/krisv'
• Action: 'org.jboss.bpm.console.client.task.LoadTasksAction'
• Exception: 'class com.google.gwt.http.client.RequestException'

HTTP 500:

HTTP Status 500 - java.lang.IllegalArgumentException: Could not connect task client

---

type Exception report

message java.lang.IllegalArgumentException: Could not connect task client

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.jboss.resteasy.spi.UnhandledException: java.lang.IllegalArgumentException: Could not connect task client
     org.jboss.resteasy.core.SynchronousDispatcher.handleApplicationException(SynchronousDispatcher.java:319)
     org.jboss.resteasy.core.SynchronousDispatcher.handleException(SynchronousDispatcher.java:230)
     org.jboss.resteasy.core.SynchronousDispatcher.handleInvokerException(SynchronousDispatcher.java:206)
     org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:360)
     org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:173)
     org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:93)
     org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:68)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
     org.jboss.bpm.console.server.util.GWTJsonFilter.doFilter(GWTJsonFilter.java:59)

root cause

java.lang.IllegalArgumentException: Could not connect task client
     org.jbpm.integration.console.TaskManagement.connect(TaskManagement.java:66)
     org.jbpm.integration.console.TaskManagement.getAssignedTasks(TaskManagement.java:179)
     org.jboss.bpm.console.server.TaskListFacade.getTasksForIdRef(TaskListFacade.java:99)
     sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
     sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
     java.lang.reflect.Method.invoke(Unknown Source)
     org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:117)
     org.jboss.resteasy.core.ResourceMethod.invokeOnTarget(ResourceMethod.java:260)
     org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:232)
     org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:166)
     org.jboss.resteasy.core.DispatcherUtilities.getJaxrsResponse(DispatcherUtilities.java:142)
     org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:356)
     org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:173)
     org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:93)
     org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:68)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
     org.jboss.bpm.console.server.util.GWTJsonFilter.doFilter(GWTJsonFilter.java:59)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.36 logs.

[grathi]

Hello

Is this issue resolved ?

I am also getting the same error...

[salaboy21]

This post is from a year ago, and we have a new tooling now, did you check that?

Cheers